Scale



Jan. 22, 1929.

H. M. CAMERON Filed July 22, 1925 SCALE 2 Sheets-Sheet 1 Jan. 22, 1929. 1,699,686

H. M, cAMERoN SCALE Filed July 22, 1925 2 Sheets-Sheet 2 gave/Moz 1" CMMI-1^.,

l edge bea rings.

Patented Jan. 22,y 1929.

UNITED STATES PATENT OFFICE.

HUGH M. CAMERON, OF WOODHAVEN, NEW YORK, ASSIGNOB. T JOHN CHATILLON & SONS, 0F NEW YORK, N. Y., A CORPORATION OF NEW YORK.

SCALE.

Application led July 22, 1925. Serial No. 45.156.

This invention relates to scales, especially of the platform type having several levers, and has for its object to give greater accuracy by removing frequent sources of error. And

s other object is to provide such a scale which is better adapted for shipment and does not have to be taken apart.

Platform scales as made today usually comprise a number of levers having knife When such a scale is moved about from one position to another, there is great danger of the knife edges or their engaging members being laterally moved to one side or the other. Lateral movement between the knife edge bearin members results in one of the bearing mem ers being moved far enough to one side until lateral engagement increases friction and error in the scale reading. It is the common practice in shipment of platform scales to demount the platform from the knife edges for protection of the knife edges in shipment. Many of the small users of scales have dillculty 1n assembling the parts received by shipment. This invention overcomes the disadvantage of assembling the scale and eliminates the error due to lateral friction in the lever bearing members.

According to this invention, the lever bearing members of a platform scale are provided with means to prevent lateral movement and to insure constant friction if any lateral thrusts are placed upon the platform. This is accomplished specifically by the use of ball bearings which have their race rings so shaped as to take up any lateral thrusts and prevent lateral movement between the bearing members.

Referring lto the drawings:

Fig. 1 shows a longitudinal section through the platform and base of my new scale.

Fig. 2 is a transverse section through the base and platform.

Fig. 3 is a top plan view of the base and levers with the platform removed.

Fig. 4 is a section through one of the ball bearings.

The platform 1() is mounted over a relatively low base in which are contained the levers actuating the indicating mechanism :ontained in the casing 12. Adjacent the corfiers of the platform are supporting columns L3 for the platform which engage ball bearngs 14. Mounted in ball bearings in the sides of the base 11 are the rods 16, one adja- :ent the front and the other adjacent the rear of the bases illustrated in the drawings. Secured on the rod 16 are the four bars or levers 17, the front two of which extend toward the indicator and the rear two levers extend in the opposite direction toward the back of the platform. The two front levers are connected by a rod as are the rear levers. The levers 17 are of the same length, and to insure simultaneous movement they are connectedby the flexible band 2O extending over and secured to the cams 18 and 19 on rods.

The ball bearings 14 and 15 are each shaped to enable any lateral thrust between the bearing members to be taken up so that there will be no movement of the platform to one side or the other nor any variation in friction resulting from movement of the platform as in prior art scales. It will also be seen that the ball bearings of Fig. 4 are almost entirely enclosed so that little or substantially no dust or dirt can get to the bearings to cause inaccuracies in weighin as is common.

Secured to the ro 16 is the lever 21 extending forwardly and joined at its end to the bar 22 leadin into the casing for actuating a spring, Welght or other means generally used in combination with an indicator, either dial or pointer.

To compensate for slight variations in length of the moment arms of the levers 17, the base of the columns 13 at the rear is recessed for co-operation with the ball bearings 14. The bases of the supporting columns 13 at the front of the platform are not round but fiat to engage the ball bearings 14 and permit slight movement of the columns 13 on the forward ball bearings with any changes in effective lengths of the levers 17. The columns 13 are located at the corners of the platform and this is made possible by having the levers 17 op ositely arranged instead of using a lever of tlie second class as is more common in platform scales. This arrangement of levers enables the platform to be supported at practicall its corners and therefore precludes the possi ility of tilting by having concentrated weight applied outside of the platform supports, and also prevents error due to shifting points of application of the weight of the platform itself as occurs when a weight is concentrated outside the platform supports. To prevent the platform and its supporting columns being moved from the ball `bearings in case the scale is turned upside down in shipment or in moving, securing means 26 may be passed under the ball bearings and fastened to the columns to tie the two together.

Within a recessed portion of the platform is the nut 23 controlling the tension of the spring 24 extending between the platform and the base. This spring is useful to hold the platform in place and prevent its coming off if the scale is turned upside down in shipment, as well as being desirable in adjusting the zero of the indicator. If the indicator does not reach zero with no load on the platform, adjustment of the nut resulting in variation of the tension of the spring 24 will serve to bring the indicator to zero.

Among the advantages of this invention may be mentioned, greater accuracy through elimination of inconstant friction especially that resultingr when relative movement occurred in the knife edge hearings to make lateral contact in one or more of the bearing members. Further elimination of error is possible by having the platform supported at its corners so that it is impossible. to place concentrated weight outside of the line between the platform lever supporting bearings and those affecting "the reading of the scale to an extent equal to one half the Weight of the platform alone. The ball bearing race Vrings or housing being accurate in cross section prevent lateral movement between the lever bearing members and pro vide a substantially constant friction in case of any thrust in the platform.

Another decided advantage in this invention resides in doing away with the necessity of demounting the platform for shipment and elimination of the consequent trouble to a small inexperienced user of scales caused by having to assemble the scale and secure proper adjustment. In this invention, the scale may be shipped as a whole and is better adapted to stand rough usage in handling than previous scales. Another' advantage includes the ease of adjustment for the indicator to bring the scale to zero by the adjustable spring between the base and platform. The base being relatively low is more compact than the usual prior art constructions and due to the platform being supported at its corners there is no likelihood of the rear end tilting as is often the case. Yet further advantages include not only the elimination of the errors referred to but greater assurance for accuracy during long life by elimination of dust and dirt from the lever bearing surfaces. The ball bearing housings can be almost completely closed to keep out dust and dirt and keep the bearing surfaces much cleaner than has heretofore been possible. Beneath the platform supporting columns flexible bands may be used to retain the platform y secured to the bearings if desired, though this is not necessary as the spring engaging the base and platform isoften sufficient means to retain the platform. A low platform scale such as this is particularly adapted as a bathroom scale.

As used herein the tei-n1 platform is not necessarily limited to a weight support which is flat.

I claim:

1. A scale comprising in combination a base, a load support, counterpoising means for said load support, means for indicating the Weight of the load, and means engaging said load support and base for pressingr the load support downward.

2. A scale comprising in combination a base. a load support, counterpoising means for said load support. means for indicating the Weight of the load. means engaging said load support and base for pressing the load support downward. and means for adjusting the pressure of said last mentioned means on the platform.

3. A scale comprising a platform, a base. a plurality of levers within said base. supporting means for the platform between said levers and platform, bearing means for said levers possessing substantially constant friction for fixing said levers against lateral movement relative to each other, said base, and said supporting means, and means substantially enclosing said bearing means against the entrance of dust and dirt to the lever bearing surfaces.

4. A scale comprising a platform, a base, levers in said base adjacent and extending to- Ward opposite ends of the platform, cams and flexible means connecting said `levers beneath the platform and means extending out from under said platform for transmitting movement of said levers to an indicator.

5. A bathroom scale comprising a low base, a projecting casing at one end of the base. an indicator within the casing, a platform upon said base, supporting means for the platform located Within the base comprising a rod on which a pair of bars are mounted for limited rotation, another rod substantially parallel with the first rod and" on which another oppositely extending pair of bars are mounted, means connecting said rods for simultaneous rotation. transmission mechanism leading from said rods to said indicator, and means within said casing for opposing rotation of said rods and bars.

Signed at New York, in the county of New York and State of New York, this 18th day of July, A. D. 1925. i

HUGH M. CAMERON.

DISCLAIMER 1,699,686.Huglt M. Gameron, Woodhaven, N. Y. SCALE. Patent dated January 22, 1929. Disclaimer filed March 4, 1940, by the assignee, The Brearley Company.

Hereby enters this disclaimer to that part of claims 1 and 2 which is in excess of the following:

l. A scale of the single platform type comprising in combination a base, a load supporting platform, counterpoising means for said platform, means for indicating the Wei ht of the load, and sprin means between the platform and the base for continuous y resiliently urgin the p atform toward the base.

2. A scale of the sing e platform type comprising in combination a base, a load supporting platform, counterpoising means for said latform, means for indicating the weight of the load, spring means between the p atform and the base for continuously resiliently urging the platform toward the base, and means for adjustably fixing the force exerted b said spring means.

[Qicz'al Gazette arch 26', 1.940.] 

